Proper front wheel alignment requires the correct setting of all of the interrelated suspension angles affecting the running and steering of the front wheels of a vehicle. Among the factors involved in front wheel alignment is toe-in. Toe-in is measured in degrees or inches. Toe-in is the difference in the distance between the front edges and the distance between the rear edges of the tires.
Correct toe-in is maintained by adjustable tie-rods. One such tie-rod construction in service has inner and outer tie-rod sections connected by an adjustment sleeve. The adjustment sleeve is threaded to both tie-rod sections. Jam nuts on the threaded ends of the tie-rod sections are tightened and torqued against the sleeve to maintain the adjustment. A stud on the outer tie-rod section must be perpendicular to the tie-rod so that the stud will be in a neutral or "0" position when it is attached to the steering arm in order to be at the proper angle to accommodate movement of the vehicle suspension. To make an adjustment requires four tools, namely, a wrench to turn the sleeve for adjustment purposes, two wrenches to apply torque to the jam nuts for tightening, and a tool to hold the stud so that the end of the outer tie-rod section is in proper position with the stud perpendicular to the axis of the tie-rod. The jam nuts in this construction can loosen and thereby destroy the adjustment.
The tie-rod assembly of the present invention is easier to adjust, requires fewer tools to accomplish the adjustment, and is not prone to loosening because the two tie-rod end sections are free to turn relative to one another. Since the parts can rotate, the problem of locking them together to make sure there is the proper perpendicular relationship is avoided because the tie-rod will be self-adjusting during use. In other words, it will seek a position where there is no torsional load. The present invention has the further advantage of eliminating one of the jam nuts.
In accordance with the specific embodiment about to be described, there are inner, outer and intermediate rod sections. The intermediate and inner rod sections are rotatably connected together. The intermediate rod section is threaded on the outer rod section and a jam nut maintains this connection.
One of the objects of this invention is to provide a tie-rod assembly having the foregoing features.
Another object is to provide a tie-rod assembly which is composed of a relatively few simple parts, is relatively inexpensive, is easy to manufacture, assemble and adjust, can be adjusted with the use of fewer tools and is not prone to loosen or require frequent readjustment.
Other objects, features and advantages of the invention will become more apparent as the following description proceeds, especially when considered together with the accompanying claims and drawings.